2017 CURE DYSTONIA NOW FOUNDATION GRANTS

Dystonia is a motor system disease characterized by involuntary postures and twisting movements. The disorder can incur significant lifelong disability to those affected and is among the top 3 conditions evaluated in neurological movement disorder specialty clinics. As yet, the precise mechanisms for dystonia are poorly understood and there are no known disease modifying treatments. Recently, we identified eIF2α signaling for a potential role in dystonia as a result of an unbiased genome-wide RNAi screen using a novel high-throughput DYT1 dystonia assay we developed. Excitingly, in subsequent mechanistic investigations, human genetics strongly supported the significance of this pathway for dystonia. Mutations in two other forms of dystonia are predicted to cause convergent eIF2α pathway signaling deficits with the mechanism we identified in DYT1 dystonia. These preliminary results lead to the overarching hypothesis that eIF2α signaling contributes to dystonia pathogenesis and enhancing its activity will be therapeutic. To test these novel hypotheses, we propose to test whether eIF2α signaling dysfunction underlies dystonia-like phenotypes in mice. Successful completion of this series of experiments has the potential to provide strong experimental support for a new signaling pathway in either or both the pathogenesis and treatment of DYT1 dystonia. Apart from knowledge that dopamine deficiency is a cellular mechanism for dystonia, few other pathway mechanisms are clearly established. The eIF2α pathway offers a number of novel druggable targets. Specific pharmacological treatments for dystonia are dearly needed. In addition, insights gained here are likely to have relevance for other forms of dystonia and ER stress-related brain diseases.

DYT1 dystonia is a neurological disorder characterized by involuntary twisting and jerking movements that usually begin in childhood. It is extremely debilitating and there is no cure. It is caused by an in-frame GAG deletion in the TOR1A gene, leading to deletion of a single amino acid in a ubiquitously expressed protein, torsinA. Although the exact functions of torsinA remain uncertain, several prior studies have suggested that it has a role as a protein chaperone in the endoplasmic reticulum. Normal torsinA interacts with many proteins and the mutation has been reported to affect multiple biological pathways. Exactly which of these biological pathways is most relevant for causing disease remains uncertain, in part because of the varying results from different experimental models with uncertain translational relevance to the disease. In this proposal, we describe the development of novel induced pluripotent stem cells (iPSCs) from fibroblasts obtained from symptomatic DYT1 dystonia patients. We also describe the differentiation of these cells into dopamine neurons, which are thought to play a key role in disease pathogenesis. Among the many different ways in which this novel resource could be exploited, one of the most valuable first steps is a comprehensive proteomics survey to delineate the spectrum of proteins and biological pathways most affected in dopamine neurons. This strategy, which is unencumbered by any specific “favorite” hypothesis regarding the most relevant proteins or pathways, is important for identifying the biological processes that are most relevant to the disease in an unbiased way.

2016 CURE DYSTONIA NOW FOUNDATION GRANTS

Cure Dystonia Now and the Dystonia Medical Research Foundation have teamed up once again, this time to better understand why a protein in the brain called TorsinA causes dystonia when abnormal due to a mutation in the DYT1 gene. Understanding the role of torsinA in dystonia may lead to new therapeutic strategies to provide relief to affected patients. We have collaborated to fund the following two research grants:

This project aims to determine a high-resolution structure of TorsinA and find yet undiscovered binding partners of TorsinA. This knowledge is necessary for rational design and development of drug candidates that specifically target TorsinA in DYT1 dystonia.

Early onset dystonia is a devastating neurological disorder that results in a range of involuntary muscle movements. According to latest estimates, about 50,000 US citizens have the disease, many of which likely undiagnosed. So far no cure has been discovered. At the root of this hereditary disease lies the enzyme TorsinA, which is subtly mutated in the patient. The goal of this proposal is to determine the atomic structure of the healthy enzyme and its mutated variant. Because an enzyme measures only a few nanometers in size (less than 1 millionth of an inch), it cannot be visualized by microscopy. Instead, it will be crystallized and measured by X-ray diffraction. The three-dimensional atomic structure will then be calculated and modeled. Visualization of the atomic structure allows for full understanding of TorsinA function and the ability to influence this function by developing specific drugs. TorsinA is an enzyme typically involved in the folding (acquiring the right structure) and/or degradation of other proteins. Curiously, the proteins on which TorsinA presumably acts are not known. In this study a novel protein labeling approach will be used; it will be dramatically more sensitive and should detect TorsinA binding partners. This exciting research project should result in the long sought-after understanding of molecular basis for the disease, the prerequisite for targeted drug design.

“Dissecting the Function and Regulation of the TorsinA-LAP1 Holoenzyme”

This proposal aims to define the molecular mechanism of torsinA assembly in the cell and identify potential torsinA binding partners using a novel method called BioID. Understanding of the molecular mechanism of DYT1 dystonia is critical for any future therapeutic interventions based on pharmacological agents that target torsinA.

The most common and severe inherited form of dystonia is DYT1 dystonia. DYT1 dystonia is caused by a mutation in the torsinA protein. This mutation is thought to inhibit the function of torsinA in nerve cells; however, the exact function of torsinA remains unknown. TorsinA resides within the nuclear envelope and is a member of a large family of protein machines that interact with other proteins. TorsinA works together with another nuclear envelope protein called LAP1, but how they function together and what other proteins interact with torsinA and LAP1 remains unknown. This is necessary to understand the mechanism of torsinA function and its role in DYT1 dystonia. To define the mechanism of torsinA function these investigators are using a sophisticated imaging technique developed to monitor single molecules in living cells. The proposed imaging experiments will allow these investigators to evaluate models of torsinA assembly and function. To identify potential partners of torsinA and LAP1 the investigators are using a recently developed method known as BioID, a method for detecting proteins that are close to each other in the cell. This project establishes a long-term interdisciplinary and collaborative effort towards understanding how torsinA works in the cell with the goal of developing potential therapeutics for DYT1 dystonia aiming at restoring torsinA function in patients.

2015 CURE DYSTONIA NOW FOUNDATION GRANT

“Evaluation of the effects of a novel nicotinic agonist, AZD1446, on neurochemical and electrophysiologic endpoints in DYT1 mouse models”

David Standaert, MD, PhD
Professor and Neurology Chair
University of Alabama

* Collaborative Funding with the Dystonia Medical Research Foundation (DMRF)

A team of American and European investigators is exploring whether a drug called AZD1446 could potentially provide relief for dystonia patients without the unintended effects frequently caused by existing pharmacological therapies. Dystonia results from improper signals in the nervous system that instruct muscles to contract excessively. Experts do not yet fully understand the neurological mechanism that causes the abnormal muscle contractions, but the origins appear to stem from an imbalance of neurotransmitters in the brain and changes in brain cell synapses. Standaert and team are using a genetically engineered mouse with abnormal neuronal signaling to examine whether AZD1446 can correct the abnormal signaling and restore the balance of neurotransmitters.

2014 CURE DYSTONIA NOW FOUNDATION GRANTS

David Eidelberg, MD, Director, Center of Neurosciences
Ji Hyun Kio, Ph.D, Research Scientist, Center for Neurosciences
The Feinstein Institute for Medical Research

Modern brain imaging techniques have provided substantial insight into the circuit abnormalities that underlie the genetic and phenotypic features of DYT1 dystonia. More recently, localized deficits in anatomic connectivity have been detected and quantified in DYT1 carriers using magnetic resonance (MR) diffusion tensor imaging (DTI) to assess fiber tract integrity in specific projection pathways. This microstructural approach, however, cannot be used to evaluate abnormal brain function at the network level. Rather, metabolic brain imaging in the resting state in conjunction with mathematical modeling can provide a useful means of identifying brain networks associated with disease processes, clinical symptoms, or both.

In this study, we aim to characterize a significant metabolic network associated with the severity of clinical signs in DYT1 dystonia patients. We will additionally define the relative importance of the component nodes of the brain network. Lastly, we will explore the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS) applied at one or more nodal targets to suppress the activity this abnormal network.

Although dystonia is characterized by involuntary contractions of muscles, the problem is not in the muscles themselves. Instead, the problem comes from the brain. For reasons that are not well understood, neurons in the brain send the wrong signals to the muscles, causing them to contract excessively. Understanding what is wrong with the signals coming from these neurons is difficult, because they are in the brain and cannot be taken out for direct examination. Very recently, new methods have been developed to study neurons outside of the human brain. This technology involves taking a small skin sample from people with dystonia, growing living fibroblasts from the skin in a dish, and then converting the fibroblasts into stem cells. The stem cells can then be used to make a variety of different types of cells, including neurons. It therefore is possible to have an unlimited quantity of different types of neurons to study for different purposes. Since these cells can be made from dystonia patients, they contain the genetic defects responsible for causing the disorder. So far we have already made these stem cells from several people with DYT1 dystonia. Our plan is to use these stem cells to make neurons, and then evaluate the biochemical and cellular processes responsible for causing them to send wrong signals. Understanding these processes will make it possible to begin to look for medications that can correct the abnormal signals.

2013 Cure Dystonia Now Foundation Grant

“Promising Treatments for Dystonia: Preclinical Testing”

Ellen J. Hess, Ph.D.
Professor of Pharmacology and Neurology
Emory University School of Medicine

Therapies for dystonia are largely unsatisfactory or palliative. Therefore, there is a tremendous need for new drugs that are truly effective for the treatment of the dystonias. Although drug discovery for dystonia was unimaginable just a few years ago, this is, fortunately, now possible in light of major advances in dystonia research. Therefore, we performed preclinical testing of several FDA-approved drugs that have promise as treatments for DYT1 dystonia. These drugs were first identified using cell-based models to find drugs with the potential to correct cell abnormalities associated with DYT1 dystonia and we then tested these drugs in mouse models of dystonia. Testing in animals helps determine if the drugs have antidystonic properties; testing in animals is also necessary to advance a drug to clinical trial. The goal of this study was to identify 1-2 promising candidates that could be used for clinical trials in patients with DYT1 or other forms of dystonia. Of the nine drugs tested, three drugs had antidystonic effects in mice. Although much work needs to be done before these drugs are useful for patients with dystonia, these drugs appear to be promising candidates for advancement to clinical trial.

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Your gift to Cure Dystonia Now will fund research toward more and/or improved treatments, and ultimately a cure, for Dystonia. We welcome and appreciate donations of any amount. Donations to Cure Dystonia Now are tax deductible as allowable by law.